MORE IDEAS FROM THE ARTICLE
Small, incremental adjustments in difficulty are almost certain to push your level up. The downside with progressive habits is that they are harder to sustain.
Minimum targeting works well for establishing long-term habits.
A goal of, for instance, doing fifty push-ups every day might not be ideal for fitness, but doing something is better than doing nothing.
Another reason to focus on the minimum is that it assumes the difficulty is in starting. To start a process can often be the hardest. Then you want to set a lower threshold to make starting as easy as possible.
Some people seem to age mostly with minds intact and others notice dramatic slowdowns. The brain appears to have a lot of redundancy built-in - known as cognitive reserve.
Education seems to have a protective effect on aging, possibly because education contributes to cognitive reserve.